diff --git a/openspec/changes/archive/2026-08-26-add-cli-help-flag/.openspec.yaml b/openspec/changes/archive/2026-08-26-add-cli-help-flag/.openspec.yaml
new file mode 100644
index 0000000..9bb4379
--- /dev/null
+++ b/openspec/changes/archive/2026-08-26-add-cli-help-flag/.openspec.yaml
@@ -0,0 +1,3 @@
+schema: spec-driven
+created: 2026-08-26
+skip_specs: true
diff --git a/openspec/changes/archive/2026-08-26-add-cli-help-flag/proposal.md b/openspec/changes/archive/2026-08-26-add-cli-help-flag/proposal.md
new file mode 100644
index 0000000..c7e0e97
--- /dev/null
+++ b/openspec/changes/archive/2026-08-26-add-cli-help-flag/proposal.md
@@ -0,0 +1,34 @@
+## Why
+
+After the first real `npm publish` attempt of `@openspec-ui/cli`
+(`2026-08-26-prepare-cli-npm-publish`), the user tried
+`openspec-ui-cli --help` to see the available options and got only
+`openspec-ui-cli: unknown command '--help' (supported: validate)` — no
+usage text at all. The options (`--cwd`, `--format`) were documented
+only in `packages/cli/README.md` on the npm registry page, not
+discoverable from the CLI itself. Any real external consumer running
+this CLI for the first time hits the same gap.
+
+## What Changes
+
+- Add a `USAGE` string and `--help`/`-h` handling to
+  `packages/cli/src/main.ts`: printed to stdout, exits `0`.
+- Also print `USAGE` to stderr alongside the existing "unknown command"
+  and argument-parsing error messages, so a mistake (not just an
+  explicit `--help`) also surfaces the available options immediately.
+- Update `packages/cli/README.md` to mention `--help`/`-h`.
+
+## Capabilities
+
+### Modified Capabilities
+
+(none in the specified-behavior sense — `validate`'s own behavior and
+exit-code contract are unchanged; this only adds a `--help` path and
+richer error output. `.openspec.yaml` sets `skip_specs: true`.)
+
+## Impact
+
+- `packages/cli/src/main.ts`
+- `packages/cli/src/main.test.ts`
+- `packages/cli/README.md`
+- `.changeset/*.md` (new changeset file)
diff --git a/openspec/changes/archive/2026-08-26-add-cli-help-flag/tasks.md b/openspec/changes/archive/2026-08-26-add-cli-help-flag/tasks.md
new file mode 100644
index 0000000..8632da3
--- /dev/null
+++ b/openspec/changes/archive/2026-08-26-add-cli-help-flag/tasks.md
@@ -0,0 +1,24 @@
+## 1. Add --help
+
+- [x] 1.1 Add a `USAGE` string (command syntax, `--cwd`/`--format`
+  options, exit-code contract) and `--help`/`-h` handling to
+  `runMain()` in `packages/cli/src/main.ts`, checked before argument
+  parsing; prints to stdout and exits `0`.
+- [x] 1.2 Print `USAGE` to stderr alongside the existing unknown-command
+  and argument-parsing error messages.
+- [x] 1.3 Update `packages/cli/README.md` to mention `--help`/`-h`.
+
+## 2. Verification
+
+- [x] 2.1 Add tests to `packages/cli/src/main.test.ts`: `--help` and
+  `-h` print usage and exit `0`; an unknown command still exits `2` and
+  now also prints usage as a second stderr line (existing assertions on
+  the first stderr line are unaffected).
+- [x] 2.2 `npm run typecheck`, `npm run lint`, and `npm run test`
+  (workspace) pass for `@openspec-ui/cli`.
+- [x] 2.3 Rebuild (`npm run build --workspace @openspec-ui/cli`) and
+  smoke-test `node packages/cli/dist/cli.js --help` directly.
+- [x] 2.4 Propose a changeset (`npx changeset`) for `@openspec-ui/cli`
+  (patch: new flag, no breaking change) instead of hand-editing
+  `version`/`CHANGELOG.md`; apply it via `npx changeset version`.
+- [x] 2.5 Run `openspec change validate --strict add-cli-help-flag`.
diff --git a/packages/cli/CHANGELOG.md b/packages/cli/CHANGELOG.md
index 176f863..8a57c39 100644
--- a/packages/cli/CHANGELOG.md
+++ b/packages/cli/CHANGELOG.md
@@ -1,5 +1,15 @@
 # @openspec-ui/cli
 
+## 0.1.2
+
+### Patch Changes
+
+- Add `--help`/`-h` to `openspec-ui-cli`, printing usage (command syntax,
+  options, exit codes) and exiting `0`. Usage is now also printed
+  alongside argument-parsing and unknown-command errors, so a mistake
+  surfaces the available options immediately instead of only an error
+  message.
+
 ## 0.1.1
 
 ### Patch Changes
diff --git a/packages/cli/README.md b/packages/cli/README.md
index 19e83e5..67b511f 100644
--- a/packages/cli/README.md
+++ b/packages/cli/README.md
@@ -17,6 +17,11 @@ npx @openspec-ui/cli validate --cwd . --format text
   to the current directory).
 - `--format json|text`: `json` (the default) prints an aggregated report
   suitable for further processing; `text` prints a human-readable table.
+- `--help` / `-h`: print this usage summary and exit `0`.
+
+```sh
+npx @openspec-ui/cli --help
+```
 
 ## Exit codes
 
diff --git a/packages/cli/package.json b/packages/cli/package.json
index 26b1975..54e1d9b 100644
--- a/packages/cli/package.json
+++ b/packages/cli/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@openspec-ui/cli",
-  "version": "0.1.1",
+  "version": "0.1.2",
   "description": "Non-interactive OpenSpec change validation for CI merge gates (see docs/adr/0007-ci-cli-third-delivery-target.md).",
   "license": "MIT",
   "repository": {
diff --git a/packages/cli/src/main.test.ts b/packages/cli/src/main.test.ts
index 2f42c42..da51eb8 100644
--- a/packages/cli/src/main.test.ts
+++ b/packages/cli/src/main.test.ts
@@ -97,4 +97,34 @@ describe("runMain", () => {
     expect(code).toBe(2);
     expect(io.errLines[0]).toContain("--format must be");
   });
+
+  it("prints usage and exits 0 for --help", async () => {
+    const io = collectingIo();
+
+    const code = await runMain(["--help"], { validateAll: vi.fn(), ...io });
+
+    expect(code).toBe(0);
+    expect(io.outLines[0]).toContain("Usage:");
+    expect(io.outLines[0]).toContain("--cwd");
+    expect(io.outLines[0]).toContain("--format");
+  });
+
+  it("prints usage and exits 0 for -h", async () => {
+    const io = collectingIo();
+
+    const code = await runMain(["-h"], { validateAll: vi.fn(), ...io });
+
+    expect(code).toBe(0);
+    expect(io.outLines[0]).toContain("Usage:");
+  });
+
+  it("prints usage alongside an unknown-command error", async () => {
+    const io = collectingIo();
+
+    const code = await runMain(["bogus"], { validateAll: vi.fn(), ...io });
+
+    expect(code).toBe(2);
+    expect(io.errLines[0]).toContain("unknown command");
+    expect(io.errLines[1]).toContain("Usage:");
+  });
 });
diff --git a/packages/cli/src/main.ts b/packages/cli/src/main.ts
index 08fe663..0fe79ab 100644
--- a/packages/cli/src/main.ts
+++ b/packages/cli/src/main.ts
@@ -5,6 +5,22 @@
 
 import { runValidateAll, type ValidateAllResult } from "./openspec-validate.js";
 
+const USAGE = `openspec-ui-cli — non-interactive OpenSpec change validation for CI merge gates.
+
+Usage:
+  openspec-ui-cli validate [--cwd <path>] [--format json|text]
+
+Options:
+  --cwd <path>        Repository root containing openspec/changes/ (default: current directory)
+  --format json|text  Output format (default: json)
+  --help, -h          Show this help and exit
+
+Exit codes:
+  0  every active change passed strict validation
+  1  at least one active change failed strict validation
+  2  the CLI itself could not complete the check (bad arguments, the
+     openspec CLI missing, a filesystem error)`;
+
 export interface MainOptions {
   cwd?: string;
   format?: "json" | "text";
@@ -58,13 +74,20 @@ export async function runMain(argv: string[], deps: MainDeps = {}): Promise<numb
   const stdout = deps.stdout ?? console.log;
   const stderr = deps.stderr ?? console.error;
 
+  if (argv.includes("--help") || argv.includes("-h")) {
+    stdout(USAGE);
+    return 0;
+  }
+
   const { command, options, error } = parseArgs(argv);
   if (error) {
     stderr(`openspec-ui-cli: ${error}`);
+    stderr(USAGE);
     return 2;
   }
   if (command !== "validate") {
     stderr(`openspec-ui-cli: unknown command '${command ?? ""}' (supported: validate)`);
+    stderr(USAGE);
     return 2;
   }